Horizontal Handoff Research Articles

A Novel Approach in 4G Mobile Technology

Due to the growth of user demands and the limitation of third generation (3G) mobile communication system, the need of fourth generation (4G) is expected. Due to the lot of features in 4G, it is better than 3G networks, some features of 4G like high speed internet, fastest data transfer, user can access internet anytime from anywhere. It does basically include the terminal ability that is different types of wireless services at anytime and anywhere. The fourth generation (4G) network will be a heterogeneous network. Here we also work on obtaining the best handoff which includes vertical handoff and horizontal handoff.

Mobility-Aware Access Strategy in Multi-User HetNets

For the user moving with high velocity in heterogeneous networks (HetNets), two aspects that cause performance degradation should be considered, one is the channel aging, the other is the handoffs. Nevertheless, only one of these two aspects is involved for performance evaluation in most of researches. In this letter, the optimal access scheme determination is investigated considering these two aspects caused by user mobility. Firstly, the vertical and horizontal handoff probability in HetNets are analyzed. Then the closed-form expressions of coverage probability considering the channel aging for both open access and closed access are derived. Combining the handoff probability and the coverage probability, a fixed data rate scheme is adopted to determine the optimal access strategy. Numerical results verify our analysis, and show that open access performs better than closed access in dense femto-tier base stations (FBSs), whereas closed access is suggested in relatively sparse FBSs. Further, for a large bias factor, the optimal access strategy depends on both the signal-to-interference ratio threshold and the user velocity.

Traffic modelling of an integrated 5G/Wi-Fi network with generally distributed user-dwell times

A traffic modelling method is proposed for an integrated 5G/Wi-Fi network with generally distributed user-dwell times. The Wi-Fi traffic can move flexibly between 5G cells and Wi-Fi cells through overflow, vertical handoff, horizontal handoff, and take-back operations. Various user dwell times are modelled by general distributions and the channel holding times are derived in terms of the Laplace transforms of the dwell times. The various arrival rates and related performance measures are derived through an algorithm of fixed-point equations. Multi-dimensional Markov processes are used to model the Wi-Fi traffic and 5G traffic and derive the steady-state probabilities through stationary symmetric queues. The traffic modelling method is applicable to the next generation of cellular systems integrated with other types of networks such as sensor networks, intelligent vehicle networks and Internet of Things applications.

Traffic modelling of an integrated 5G/Wi-Fi network with generally distributed user-dwell times

A traffic modelling method is proposed for an integrated 5G/Wi-Fi network with generally distributed user-dwell times. The Wi-Fi traffic can move flexibly between 5G cells and Wi-Fi cells through overflow, vertical handoff, horizontal handoff, and take-back operations. Various user dwell times are modelled by general distributions and the channel holding times are derived in terms of the Laplace transforms of the dwell times. The various arrival rates and related performance measures are derived through an algorithm of fixed-point equations. Multi-dimensional Markov processes are used to model the Wi-Fi traffic and 5G traffic and derive the steady-state probabilities through stationary symmetric queues. The traffic modelling method is applicable to the next generation of cellular systems integrated with other types of networks such as sensor networks, intelligent vehicle networks and Internet of Things applications.

1149 Retrieval Number: B7631129219/2019©BEIESP DOI: 10.35940/ijitee.B7631.129219 Journal Website: www.ijitee.org Published By: Blue Eyes Intelligence Engineering & Sciences Publication An Improved Algorithm for Handover in LTE Heterogeneous Networks

The transition from 3G to 4G has been a gradual process all these years and in developing countries like India, the change has to span even longer. Eventually, at lot of places while moving we come across signal variations which force the handoff to be decided. The handoff may be vertical or horizontal but it has to be seamless and service continuity cant be ignored anytime. This research proposes a handoff mechanism which takes certain parameters like RSS, node-speed, network cost, network latency, bandwidth and throughput before deciding the handover. This research does a simulation in MATLAB to analyze the effect of these parameters on handover decision both in homogenous and heterogeneous networks. The simulation virtualizes a scenario where a node moving in a geographical region experiences multiple handoffs both vertical and horizontal, based on the above-mentioned parameters. The simulation successfully proves that the proposed methodology performs seamless vertical and horizontal handoffs. The simulation is performed on two different scenarios where the former does handoff between 3G and 4G networks (vertical handoff) and the latter takes a WIMAX and 4G LTE network into consideration. The results are presented in terms of RSSI, throughput and bandwidth and performance of LTE is compared with 3G & WIMAX technique. The performance of the technique has been represented graphically each graph showing variation in handoff decisions for different values of a particular parameter.

A new method for handoff target network selection

In wireless communications of fourth generation the expectation to assimilate a hypothetically numerous heterogeneous wireless technologies are happened under consideration of a novel step toward worldwide smooth access. The advancement in wireless networks increases the challenges of mobility management as well the challenges of merging a various number of wireless networks. Out of those the main challenge for smooth movement is the accessibility of consistent vertical (intersystem) and horizontal (intra-system) handoff processes. So to improve the quality of service and to provide always best connected services all the time, the handoff decision algorithm must select an optimum target network from the available candidate networks. The purpose of this paper is to provide a mechanism for selecting an optimum target network from the available networks. This method is devised for maximizing the user satisfaction level, by selecting the “best” network as the handover target network among multiple candidate networks.

Handoff in Various Mobile Network Technologies

Mobile cellular networks are an indispensable part of modern life, where the need for customer satisfaction in the use of many different services by consumers is constantly increasing. The requirements for higher transmission speed, lossless transmission, reliability, efficiency, low latency, mass connectivity, guarantee of high Quality of Service criteria are repeatedly increasing. All this requires the continuous development of the used technologies as well as the introduction of new generations of networks. Handover mechanism is extremely important in cellular network because of the cellular architecture employed to maximize spectrum utilization. To ensure the quality of service in wireless cellular networks, the report proposes the use of a Horizontal Handoff Priority Scheme. Simulation experiments have been carried out, the probability parameters of the scheme have been evaluated and the probabilities of losses occurrence have been classified as rare events. The proposed material are various algorithms and techniques for the implementation of Vertical and Horizontal Handoff in 3G, 4G and fifth-generation networks to provide the required QoS for mobile users with Ultra-High Definition.

An Equivalent Analysis for Handoff Probability in Heterogeneous Cellular Networks

In heterogeneous cellular network (HCN), mobile users may travel across the coverage of different base stations (BSs). Handoff procedures need to be performed to maintain seamless connectivity. Since BSs in different tiers have distinct setting about transmission power and range extension bias, analysis for the network performance becomes complicated, particularly for the vertical handoff as an important functionality in HCN. To facilitate performance analysis, this letter proposes a method built on the equivalence between vertical handoff and horizontal handoff events. With the established equivalence, both types of handoff probabilities can be obtained in a single analytical framework. We also derive the coverage probability of mobile users by including the handoff cost in the analysis and obtain a compact expression. Numerical results are presented to validate the analysis accuracy and provide insights to the performance of HCN in supporting mobility.

Maximizing QoS by cooperative vertical and horizontal handoff for tightly coupled WiMAX/WLAN overlay networks

In the past few years, the deployment of WLAN proliferated throughout the world due to easy installation, low cost and higher bandwidth. The latest IEEE 802.11 standard (802.11n) offers the maximum data rate of about 600 Mbps which makes it an accepted benchmark for deploying WLANs. One of the disadvantages in WLAN is its small coverage which is not suitable for mobiles with high velocity. The alternate network technology for WLAN with almost equal bandwidth and QoS support with wider coverage area is WiMAX, which is one of the rapidly growing technologies across the world. Hence, the integration of WiMAX and WLAN is considered to be a sound approach in 4G. In this paper, we present handoff and integration related issues in WiMAX/WLAN overlay networks, numerical methods for calculating network conditions of both WiMAX and WLAN networks and impact on 802.11n clients by legacy 802.11a/b/g clients. Also, we propose QoS based proactive handoff algorithms for WiMAX/WLAN overlay networks which performs both vertical and horizontal handoffs based on the network condition, acceptable packet delay, required bandwidth and client type. Simulation results demonstrate that the proposed handoff algorithm enhances the QoS significantly.

Seamless Vertical Handoff using Invasive Weed Optimization (IWO) algorithm for heterogeneous wireless networks

Abstract Heterogeneous wireless networks are an integration of two different networks. For better performance, connections are to be exchanged among the different networks using seamless Vertical Handoff. The evolutionary algorithm of invasive weed optimization algorithm popularly known as the IWO has been used in this paper, to solve the Vertical Handoff (VHO) and Horizontal Handoff (HHO) problems. This integer coded algorithm is based on the colonizing behavior of weed plants and has been developed to optimize the system load and reduce the battery power consumption of the Mobile Node (MN). Constraints such as Receiver Signal Strength (RSS), battery lifetime, mobility, load and so on are taken into account. Individual as well as a combination of a number of factors are considered during decision process to make it more effective. This paper brings out the novel method of IWO algorithm for decision making during Vertical Handoff. Therefore the proposed VHO decision making algorithm is compared with the existing SSF and OPTG methods.

Improved joint radio resource management usage grey fuzzy control in heterogeneous wireless networks

This paper presents an innovative approach to joint radio resource management (JRRM) over a complex heterogeneous network by using several realistic radio access technologies (RATs). This work applies a novel grey fuzzy control process to joint radio resource management (JRRM). In this architecture, the JRRM techniques are divided between grey fuzzy control (GFC) and grey fuzzy multi-attribute decision making (GFMADM). These enhancements lead to a new JRRM architecture which seeks to minimize the multi-user interference, decrease blocking, lower dropping probabilities and improve load balancing. The policy uses the signal strength, path loss, and load algorithms for admission control (AC), horizontal handoff (HHO) and vertical handover (VHO) in a heterogeneous wireless scenario which includes GSM/ EDGE radio access network (GERAN), high-speed packet access (HSPA) and long term evolution (LTE) RATs. Our simulation results show that the proposed GFC/GFMADM algorithm can decreases multi-user interference which results in the increasing system radio capacity, decreasing blocking and dropping probabilities and enhancing load balancing.

Modified handoff algorithm for providing optimization in heterogeneous wireless networks

In this study, the heterogeneous wireless network is considered. Obviously, it is an integration of two different access networks, namely cellular and WLAN. In the heterogeneous wireless networks, handoff is an important process when the user moves from one network (3G) to another network (WLAN). While the user is moving, the mobile nodes (MN) move within the coverage area of WLAN and 3G with different velocities. When user migrates between heterogeneous networks, for best performance, the seamless vertical handoff (VHO) is very essential. In this paper, we propose a modified optimization (M-OPTG) based VHO or horizontal handoff (HHO) algorithm for the heterogeneous wireless networks. The performance of M-OPTG algorithm with load, battery life time, velocity and call dropping analysis have been investigated. Some of the existing VHO or HHO algorithms provide only analytical results. In this paper, we have developed a real time study using network simulator to choose the appropriate network for providing service to a MN. Our proposed (M-OPTG) VHO or HHO algorithm provides better performance on the basis of battery life time, load balancing, call dropping probability and minimizes the number of handoffs based on the velocity of the MN. The Modified OPTG algorithm not only improves the collective battery life time of a MN, but also reduces the call dropping probability and unnecessary handover.

Survey of different Solutions for Simultaneous Mobility Problem using mSCTP Protocol

generation wireless network need the support of all the advances on new architectures, standards, protocols. Mobility management is an important issue in the area of mobile communication. Mobility management is divided into two parts, first one is Location management and second one is Handoff Management. Again Handoff management is divided into two parts, Horizontal handoff and Vertical handoff. In today's mobile communication era, in case of simultaneous mobility, achieving seamless handoff is very important task. In this article we surveyed different simultaneous mobility issues using mSCTP protocol with different solutions. KeywordsMobility, mSCTP, Handoff Management, Location Management, Seamless handoff, Binding updates.

Dynamic target wireless network selection technique using fuzzy linguistic variables

Even though various wireless Network Access Technologies (NATs) with different specifications and applications have been developed in the recent years, no single wireless technology alone can satisfy the anytime, anywhere, and any service wireless-access needs of mobile users. A real seamless wireless mobile environment is only realized by considering vertical and horizontal handoffs together. One of the major design issues in heterogeneous wireless networks is the support of Vertical Handoff (VHO). VHO occurs when a multi-interface enabled mobile terminal changes its Point of Attachment (PoA) from one type of wireless access technology to another, while maintaining an active session. In this paper we present a novel multi-criteria VHO algorithm, which chooses the target NAT based on several factors such as user preferences, system parameters, and traffic-types with varying Quality of Service (QoS) requirements. Two modules i.e., VHO Necessity Estimation (VHONE) module and target NAT selection module, are designed. Both modules utilize several “weighted” users' and system's parameters. To improve the robustness of the proposed algorithm, the weighting system is designed based on the concept of fuzzy linguistic variables.

A Movement based Algorithm for Determining Handoff in Heterogeneous Wireless Networks

The Next Generation wireless networks generally called 4G Networks will most likely be actualized by the Integration of present day available heterogeneous wireless networks. Integration of these networks will largely depend on the process of vertical handoff. Vertical handoff occurs when an active communication session is transferred between different radio access technologies. An efficient assessment system is essential for appropriate network selection.Unlike horizontal handoff, vertical handoff only takes place in cell edges. There are many other factors that should be considered for a proper vertical handoff i.e., triggering factor, critical factor and influencing factors. For that an efficient assessment system is essential for appropriate network selections. The vertical handover problem has been becoming increasingly interesting due to its practical value. The convergence of heterogeneous wireless access technologies characterizes the 4G wireless networks. In such systems the seamless and efficient handoff between different access technologies is essential and remains a challenging problem. This paper presents a Movement based algorithm (MBA) for determining handoff in heterogeneous wireless networks. Our algorithm addresses to cellular as well as broadband mix systems for randomly generated users. Our algorithm determines pathloss, throughput and signal-tonoise- ratio (SNR) between randomly generated users, Access points (APs) and Base stations (BS). The proposed method is well suited for networks systems, it eliminates the rigorous mathematical expressions and its design is simple and straightforward.The main goal of our algorithm is to enhance or improve the system performance in terms of higher throughput for the required networks (BWN and WiMax). Simulation work has been carried out in the MATLAB environment. Simulation results significantly outperform the existing algorithms. We haven’t used any MATLAB toolbox. In fact we developed our own simulation platform in MATLAB. Simulation results confirm that our algorithm improves higher throughput by 14.8 % compared to other existing approaches.

Performance Modeling of an Integrated Wireless Network Using WiMAX as Backhaul Support for WiFi Traffic

We propose an analytic model for an integrated wireless network using WiMAX as backhaul support for WiFi traffic and evaluate the system performance. A unique feature for the proposed model is that the WiFi traffic completely reflects the realistic user mobility. A WiFi call can be overflowed to its overlaid WiMAX cell when it is rejected at the WiFi cell; a WiFi call may also work for some period of time in the WiFi cell and then make a vertical handoff to its overlaid WiMAX cell when it wants to move from its current WiFi cell (e.g., office) to its target WiFi cell (e.g., airport). Further, the target WiFi cell may be located at another place in the same WiMAX cell, or at a different WiMAX cell. We use Markov processes to model the dynamics of the WiMAX traffic and WiFi traffic including the overflowed WiFi traffic, the vertical handoff WiFi traffic, the horizontal handoff WiFi traffic, and the take-back WiFi traffic. We derive the explicit expressions of various traffic arrival rates and performance metrics and analyze the performance improvement of the WiFi traffic and the impact on the WiMAX traffic due to backhaul support. Numerical results are provided for further understanding of the gain and loss of the integrated architecture.

Joint radio resource management in heterogeneous wireless networks by using combined fuzzy logic and MADM

This paper addresses a novel mechanism to solve the scalable problem in JRRM. Due to the flexibility and simplification, the fuzzy logic control (FLC) is chosen to make effective utilisation of resources. The combined fuzzy logic and multi-attribute decision making (MADM)-based algorithm can make proper initial RAT selection, horizontal handoff, vertical handoff, admission control and load balancing. The MADM-based RAT selection also has better efficiency than the traditional RRM mechanisms. By considering three kinds of traffic, voice, video and data respectively, the proposed scheme provides lower new call blocking probability and handoff call dropping probability in the heterogeneous wireless network that includes GSM/EDGE radio access network (GERAN), high-speed packet access (HSPA) and mobile worldwide interoperability for microwave access (WiMAX) RATs.

Novel Handoff Method for the Integrated 3G and Nemo Network

This paper aims to revise the handoff method for integrated 3G and NEMO network. The method includes horizontal handoff and vertical handoff for the heterogeneous wireless network. This paper took advantage of the NEMO’s characteristics to propose a novel horizontal handoff method. We adopt the conception of hierarchical network to design a vertical handoff method. Our method decreases handoff latency, network latency and control packets for handoff. The simulated results demonstrate our method is better than the traditional NEMO.

A Location-Aware Vertical Handoff Algorithm for Hybrid Networks

One of the main objectives of wireless networking is to provide mobile users with a robust connection to different networks so that they can move freely between heterogeneous networks while running their computing applications with no interruption. Horizontal handoff, or generally speaking handoff, is a process which maintains a mobile user's active connection as it moves within a wireless network, whereas vertical handoff (VHO) refers to handover between different types of networks or different network layers. Optimizing VHO process is an important issue, required to reduce network signalling and mobile device power consumption as well as to improve network quality of service (QoS) and grade of service (GoS). In this paper, a VHO algorithm in multitier (overlay) networks is proposed. This algorithm uses pattern recognition to estimate user's position, and decides on the handoff based on this information. For the pattern recognition algorithm structure, the probabilistic neural network (PNN) which has considerable simplicity and efficiency over existing pattern classifiers is used. Further optimization is proposed to improve the performance of the PNN algorithm. Performance analysis and comparisons with the existing VHO algorithm are provided and demonstrate a significant improvement with the proposed algorithm. Furthermore, incorporating the proposed algorithm, a structure is proposed for VHO from the medium access control (MAC) layer point of view.

Seamless handoff scheme in Wi-Fi and WiMAX heterogeneous networks

With the development of wireless communication technology, various wireless networks have been deployed. Heterogeneous networks will be dominant in the next generation wireless networks. In such networks, providing a seamless handoff and quality of service (QoS) guarantees is one of the key issues for real-time services. In this paper, we propose a horizontal handoff scheme that reduces the horizontal handoff latency based on the location and movement pattern of a mobile node (MN). We also present a vertical handoff scheme for providing seamless services between Wi-Fi and WiMAX networks. Finally, by performance evaluation using computer simulations, we show that the proposed scheme can reduce the handoff latency significantly.